Incandescent electric light.



1 Tim and THOMAS F. MoDnRi/IOTT, citizens ofv patinar entre.

WALTER .I. CARPENTER AND THOMAS F. McDERMOTT, OF PROVIDENCE, RHODE ISLAND.

INCANDESCENT ELECTRIC LIGHT..

Specification of Letters Patent.

Patented April 2'7, 1909.

f ,application filed August 1 6, 1907. seriai No. 388,347.

i To all ywhom may concern:

Be it known that we, WALTER J. CARPEN- the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented a new and useful Iniprovement in incandescent Electric Lights, of which the following is a spec'ilication.

This invention has reference to an improvementv in incandescent electric lights and more articularly to an improvement in an incant escent electric lamp bulb and socket.

The object of our invention is to improve the constructioncf a combined high and low power incandescent electric lamp bulb `and socket, whereby the lamp is adapted to give a high power hght, a low power light or an intense light equal to the combined power of both the high and low power lights.

Figure 1 is a View looking at the head end of the bulb and showin@r the-'two coiitact plates. Fig. 2 is a viewlooking at the end of the socket and showing the two corresI'ponding contact arms 1n the socket, andig. 3 is a vertical side view of the bulband socket partly in section, showing the twin contact plates on'the bulb in contact with the twin contact arms in the socket, the high and low power filaments in thebulb and the wiring of the bulb and socket.

The light bulbd has the usual base end in the form of a screw-threaded shell 9, the two contact plates 10 and 11 on the end of the base and insulated from the shell 9 and from each other by an insulating cap, 12 forming 15 which is connected to the shell 9 by solder or other means 'lhe other end of the high power lilznnent 13 is connected to a wire 16 which is connected to the contact plate 10 and the other end of the low power filament 14 is connected to a wire 17 which is connected to the contact plate] l, shown in Fig. 3.

lhc socket. e comprises a shell 1S adapted to be secured in the required position and having a central insulating block 19 to the outer end ol' which is secured a scre\\'tln'ead ed shell 20 for the light bulb d. Block 19 is of solid constructimi and has plain bounding sides. A contact member 21 is secured to tion to form `an electrical contact u ith the closed end of the shell `20, and a wire '22 is connected to the contact. member 21 being connected'to a suitable source ol electrical supply. An L-shaped s ning contact arm 23 having the enlarged enc 24 is secured to the side of the insulating block 19 in a position for the enlarged end 24 to extend through an opening in the side of the shell 2O and come into electrical Contact n ith the contact plate 11 on the base of the light bulb d. A. wire 25 `is connected to the contact arm 23 and leads to the switch which controls the flow of current through the filaments. An L- shaped spring contact arm 26 having the enlarged end 27 is secured to the side of the insulating block 19 in a position for the enlarged end 27 to extend through an opening in the side of the shell 20 and come into electhe side of the insulating block 19 in a positrical Contact with the contact plate 10 on the base of the light bulb d. A wire 28 is connected to the contact arm 26 and to the said controlling switch.

The light bulb d is secured by screwing the screw-threaded shell 9 oi the base into the screw-threaded shell 2() of the socket until the contact plates 1() and 11 on the base come into 'electrical contact with the enlarged ends of the spring contact arms and 2.6, as shown in Fig. 3. The high power filament 13 may be of sixteen candle power and the low power filament `14 of two or four candle power.

Having thus described our invention, we claim as new and desire to secure by Let-ters Patent ,-f

In anincandcsccnt electric light, a bulb having a screw threaded shell, an insulating cap on said shell, a pair of oppositely arranged spaced contact plates on the outer end face oi said cap, a high and a low power filament in said bulb, a wire connecting one end of the high power and one end otI the low power filament with a point on one side of said shell at a distance from said cap, a second win` connected to the other end of the high power filament extending through said shell and secured to onc'of said contact plates. a third wire connected to the other end oll the low power iilamont extending through sind shell and secured to the other oi' said contact plates, a socket composed of a shell, a central insulating block secured lo said shell, said insulatingr block being oi solid construction and having plain bounding sides, a screw threaded shell secured to' said block, a contact member secured to said block at one side thereof adjacent to said last named shell, a pair of oppositely arranged Leshaped spring contact arms secured to the block sides on opposite sides of said Contact niembcr and having their free ends extending on .the under face of the block and passed through openings provided therefor in the socket she l, the free-ends of said springcontact arms being spaced apart a distance approximately e ual to` the distance be-A tween said pair o contact plates and being adapted to seat on the outer faces of the 15 latter, a pair of'wires disposed onthe outer sides of said insulating blocliand connected to said arms, and a third Wire disposed on the outer face of said block bctween said pair ol' Wires and connected to said Contact member, all of saidA Wires beingdisposed on the in, terior of said socket shell.

In testimony whereof we have signed our names to this speciication in the presence oi' two subscribing witnesses.

WALTER J. CARPEN TER THOMAS F. MCDERMOT'I Witnesses: i

ADA E. HAGERTY, J. A MILLER. 

